Heel dowel construction



April 20, 1965 w. o. BURKE ETAL 3,178,835

HEEL DOWEL CONSTRUCTION Filed Oct. 18, 1963 United States Patent O 3,l78,835 HEEL DQWEL @ONSTRUCHN William 0. Burke, Rockford, and Robert Z. lluntic, Elmhurst, lll., assignors to National Lock Co., Rockford,

Ill., a corporation of Delaware Filed Get. 18, 1963, Ser. No. 317,243 6 Claims, (Cl. 36m-3i) The present invention relates to a shoe heel and more particularly to a replace-able lift construction including a novel heel dowel for attaching the left to the heel of a Womans shoe.

Fashionable designs in womens shoes in recent years have tended more to those generally referred to as spike heels which have a very small cross Section at the ground engaging end or heel lift. The heels require lifts rat the lower ends or tips which have substantially greater wearability than the material `forming the heel and can be easily replaced when worn to provide an inexpensive means of preserving the condition and appearance of the heel of the shoe.

Lifts have been made of leather which are nailed directly to the heel or of a relatively tough hard plastic molded onto a dowel or other suitable means of attaching the lift to the heel. Recently, lifts have been formed of more resilient plastic material or natural or synthetic rubbers of a relatively flexible characteristic. These materials are molded onto heel dowels having heads with an annular .groove or undercut surface in an endeavor to provide additional engagement between the lift material and the heel dowel.

An impor-tant object of the present invention .is the provision of a novel heel dowel construction having an enlargement or head so constructed and designed as to effect a positive interlock with the molded material utilized to form the heel lift. The heel dowel head is a cylindrical cup with slots cut in its side walls to form vertically spaced upper and lower annular anges. The lift material envelops the head and flows through the slots and into the central recess of the cup to form a most effective mechanical interlock with the head. This mechanical in'terlock has been found to be far superior to prior heel dowels having an annular groove around the head since the lift material iiowing or projected into the lgroove may be easily yand readily withdrawn so that the lift becomes disengaged rom the heel dowel under pressure.

A further impor-tant object of the present invention is the provision of a novel heel dowel affording increased structural adequacy against impact forces normally imposed in use. The novel heel dowel comprises a cylindrical cup member slotted to provide vertically spaced annular ilanges with the upper and lower annular flanges engaging the resilient lift material in laminar fashion, so lthat the upper annular flange reinforces the lower annular ilange absorbing a portion of the stresses imposed thereon and transmitting them on to the dowel sha-nk. Furthermore, the llat top surface of the upper annular ilange is separated from the lower surface of the heel by a layer of the resilient lift material thereby providing a cushioning effect which absorbs impact shock and pre-vents a portion 4thereof from being transmitted into the heel.

Another important object of the present invention is the provision of a heel dowel having a head capable of being formed of smaller dimens-ions than prio-r known heel dowels and yet effect a greater retention or holding power with the lift than with prior known dowels. Thus, the present heel dowel is more versatile and can be utilized on the smaller heels and ground engaging lifts without reducing the conventional shank diameter of the dowel.

A further object of the present inven-tion is the provision of a heel dowel capable of presenting a greater thickness of wearing material below the lower surface of ICC the head ofthe dowel than in prior structures without sacrificing the greater holding power or retentive capability between the lift material and the heel dowel. Consequently, replacement of the lifts will occur at less frequent intervals lthan with prior known dowels resulting in longer life. l

The present invention also comprehends the provision of a heel dowel which is inexpensive to make and to which may be easily and most effectively molded a plastic or resilient lift -to provide a heel lift assembly which is easily and quickly lattached to a shoe heel by driving Vand :anchoring ythe shank of .the dowel into a preformed hole in the heel.

The present invention further comprehends the provision of a heel do-wel having a head formed as a cylindrical cup with slots cut in its side walls provid-ing greater interlocking ilow areas ythan comprehended in prior dowels and `thereby provide ya more secure interlock between the molded lift lmaterial flowing into and through these connected openings and the head of the heel dowel.

Thus, the disclosed novel embodiment of a heel dowel, as compared to prior forms of heel dowels, has numerous advantages thereover among which are the following:

(l) The cup-shaped slotted head is smaller in diameter or cross section affording; (a) smaller heel sizes, (b) more lift material around Itithe head of the dowel, (c) more lift material under the head of the dowel.

(2) Transverse slots opening into the hollow head, which slots are substantially larger in area atiording a more etiective interlock between the dowel head ,and the lift material.

(3) More effective structurally due to reinforcing eilect of upper ilange.

(1i) The upper annular ange affords addition-al envelopment of the dowel head by the lift material.

Further objects are to provide a construction of maximum simplicity, efficiency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.

ln the drawings:

FIGURE 1 is a View partially in vertical cross section of a heel for a womans shoe having the heel dowel and lift of the present invention aiiixed to the heel.

FIG. 2 is an enlarged fragmentary view of the lower end of the heel shown in FIG. 1 with the heel dowel and lift applied thereto.

FIG. 3 is a horizontal cross sectional View taken on the line 3-3 of FIG. 2 and viewed in the direction of the arrows, showing the interlock between the lift and the head of the heel dowel.

FIG. 4 is a horizontal cross sectional view taken on the line 4i- 4 of FIG. 2 and viewed in the direction of the arrows.

FIG. 5 is a vertical cross sectional view taken on the irregular line S-S of FIG. 3 to further show the construction of the head of the heel dowel.

FIG. 6 is a fragmentary View, part in side elevation and part in vertical cross section, of the headed end of the heel dowel.

Referring more particularly to the drawing wherein is disclosed an illustrative embodiment of the present invention, FIG. l discloses a heel 10 formed of a plastic composition or other suitable material having an upper surface il shaped to conform to the configuration of ladys shoe with the heel body narrowing to a lower end 12 of a relatively small cross sectional area. A heel lift member i3 is attached to the lower end 12 to provide the ground or floor engaging surface for the heel.

The lift member includes a heel dowel 14 having an elongated shank or stem l5 which is inserted into an elongated performed hole or bore 16 in the heel 10 and composition or a natural or synthetic rubber, such as' polyurethane rubber.

The elongated shank or stem 15 has a generally conicalY pointed end 19 which is inserted into the `heel 10 and longitudinally extending knurling 21, and spaced axially therefrom, a relatively short knurled portion 22. rlhe knurled portions 21 and 22 preventthe dowel 14 from turning Vwhen driven into an opening in the heel body and aid in securing the lift member 13 to the heel as the knurled portions are preferably of a slightly greater diameter than the 4diameter to the preformed hole or bore 1 6. Y

The opposite end of the shank terminatesrin an enlarged hollow head 17 with an intermediate cylindrical portion 23 of slightly largerdiameter than the shank 15 between the hollow head and shank. The enlarged hollow head 17 is shown formed as a cylindrical cup slotted to provide an upper annular flange 25 vertically spaced from a lower annular flange 26. A relatively large centralrecess 27 extends axially through the enlargement or head from the lower annular flange 26 as shown in FlGS. 5 and 6, and opposed relatively deep slots 2S, 28 extend through the hollow head or cup where they provide relatively large radially extending openings between the vertically spaced flanges 25 and26 communicating with the central recess 27 between the residual connecting web portions 29.

VThe sides of these slots 28 are parallel and each provides an arcuate opening to the central recess. slotting operation removes substantially sectors of the side wall formed by the central recess of the cylindrical hollow head and provides axially spaced horizontally arranged parallel surfaces. The lift material 1S when molded about and through the enlarged hollow head 17 of the heel dowel 14 has its material flowing completely about and enveloping the head, and into the central recess 2'7 and through the large'communicating opposed arcuate slots 28 to form an integral and connected body Y of material having a positive mechanical interlock with the head 17.

As clearly shown in the drawing, the resilient lift material completely encompasses and envelops the projected cupped head 17 of the heel dowel whereby an upper layer 31 of the lift material 18 disposed between the upper surface of the upper anular llange 25 and the lower surface of the end 12 of the heel body, provides a cushioning elect which absorbs impact shock and prevents a portion of the shock from being transmitted into the heel proper.

Due to the small diameter or cross section of the head 17, a substantial thickness of the lift material 18 is disposed around and Vunder the dowel head, thereby materially increasing the :wearing qualities and life of the lift as well as absorbing impact shock to which the lift is subjected in use. A

The present heel dowel utilized with the heel lift for the heel of a ladys shoe has the following important advantages:

(1) The head on the heel dowel is smaller in diameter or cross section than heel dowels presently known and thus adapted for use onV smaller lifts and smaller heeels. Y (2) Provides more wearing material between the headed end of the heel dowel and the lowerl or ground engaging surface of the lifty and, consequently, longer life before requiring replacement.

(3) The hollow interior or bore and theV communicating transverse slots of the present heel dowel are larger in area and more effective in the retention of the molded lift than `those of prior known devices.

The

(4) The present heel dowel is cheaper and easier to manufacture as the communicating tranverseA slots are made by broaching, milling or the like, and the recess or bore in the hollow cylindrical head cold headed or impact extruded, whereby any machining operations are reduced to a minimum.

Having thus disclosed the invention, we claim:

1. A heel dowel for mounting a moldable heel lift onto the heel of a shoe having a preformed opening therein, comprislng an elongated shank for insertion into the preformed opening, and an integral hollow cylindrical head on the end of said shank having acentral longitudinal cylindrical bore therein opening to the lower end of the headvand radially extending slots formed in the periphery of the head intermediate its ends and intersecting and opening into said central bore to form vertically spaced annular flanges and a mechanical interlock between the heel lift Vand said cylindrical head where the Vheel lift material flows into and through said slots and said central longitudinal bore and completely envelops and interlocks with said head.

VZIA heel dowelas set forth in claim 1, in which said central longitudinal bore extends upwardly into said head to adjacent the junction of said head'with said shank.

3. A heel dowel as set forth in claim 1, in which the spaced annular flanges engage the lift material in laminar fashion with the upper annular llange reinforcing the lower annular flange and absorbing and transmitting irnposed stresses to the' shank of the dowel and a layer of Ylift material is disposed between the lower surface of the heel and the upper surface of the upper flange providing Va cushioning effect and absorbing impactrshock.

4. A heel dowel as set forth in claim 1, in whichl said slots formed in the periphery of they cylindrical head have substantially theconliguration of sectors of an anto form an integraly unit, said cylindrical head having a central longitudinal cylindrical bore extending from adjacent the junction of theY head and the elongated shank `to and opening in the lower end of said head and elongated generally radially extending opposed slots formed p in the periphery of the head intermediate its ends intersecting and opening into the central longitudinal bore, said slots forming spaced upper and lower annular flanges each having outer diameters equal to the diameter of said head and inner diameters equal to the diameter of the central bore, said heel lift being formed of a moldable material completelyvenveloping the cylindrical head and extending into and throughfsaid elongated slots and said central cylindrical bore torprovide a Vmechanical intere lock ywith the head of the heel dowel, said lift material extending over the upper annular ilange providing a cushioning-means for absorbing impact shock and providing a substantial thickness of material around and below the head. l

6. In a heel dowelassembly as set forth in claimk 5, in which said elongated radially extending slots are separated by opposedresidual web members forming part of v the head and joining said upper and lower annular flanges.

References Cited bythe Examiner UNITED STATES PATENTS JORDAN FRANKLIN, Primary Examiner. FRANK J. COHEN, Examiner.

ATE S PATENT OFFICE UNITED ST CERTIFICATE OF CRRECTION Patent No 3,178 ,835 April 2O l965 William O. Burke et al. It is hereby certified that error appears in the above numbered pattion and that the said Letters Fatent should read as ent requiring correc rested below.

d -lit column 2,

line

line 9, Jor left" rea Column l, line 72 Jfor "performed" read preforme l7 for "to" read o same column line 67, read heels Signed and sealed this Zlst day of September 1965.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER Attesting Officer for heeels 

1. A HEEL DOWEL FOR MOUNTING A MOLDABLE HEEL LIFT ONTO THE HEEL OF A SHOE HAVING A PERFORMED OPENING THEREIN, COMPRISING AN ELONGATED SHANK FOR INSERTION INTO THE PREFORMED OPENING, AND AN INTEGRAL HOLLOW CYLINDRICAL HEAD ON THE END OF SAID SHANK HAVING A CENTRAL LONGITUDIANL CYLINDRICAL BORE THEREIN OPENING TO THE LOWER END OF THE HEAD AND RADIALLY EXTENDING SLOTS FORMED IN THE PERIPHERY OF THE HEAD INTERMEDIATE ITS ENDS AND INTERSECTING AND OPENING INTO SAID CENTRAL BORE TO FORM VERTICALLY SPACED ANNULAR FLANGES AND A MECHANICAL INTERLOCK BETWEEN THE HEEL LIFT AND SAID CYLINDRICAL HEAD WHERE THE HEEL LIFT MATERIAL FLOWS INTO AND THROUGH SAID SLOTS AND SAID CENTRAL LONGITUDINAL BORE AND COMPLETELY ENVELOPS AND INTERLOCKS WITH SAID HEAD. 